Improved process of electroplating iron, steel



UNITED STATES PATENT OFF CE.

UIIARLES BESLAY.OF PARIS, FRANCE, Assienon To EDWARD HEGKSHER.

IMPROVED PROCESS OF ELECTROPLATING IRON, STEEL, 0.

Specification forming part of Letters Patent No. 36,750, dated October21, 1862.

To ((1 l whom 'it may concern:

Be it known that I, CHARLES BESLAY, of

Paris, in the Empire of France, have invented certain new and usefulImprovements in Electroplating Iron or Steel; and I hereby declare atthe'ordinarytemperature (if above the freezing-point) and by usingsolutions not concentrated.

My invention therefore consists in the new application or adaptation ofmeans and of electro-chemical manipulations already knowni. 6., incombining the several processesso as to efi'ect in an industriallypractical manner galvanization of metals at the ordinary temperature, orwhat I term the cold.

In carrying out'my invention I avail myself of the law of aflinity whichsome metals in a greater or less degree have for other metals. Forinstance, it is well known that certain metals will readily combine withcertain others by way of fusion, while others may with facility bedeposited in a metallic state by electro-chemical process.

Now, iron forms with tin a series of alloys in which either the iron orthe tin predominates. In the combination of these two metals theproductor the alloy presents well-defined characteristics, constitutinga homogeneous mass difl'ering essentially from either of theirconstituents. Such will not be the result when iron is being combinedwith zinc or lead or copper; but since tin may be readily united withiron I first cover the iron with tin for the such metal to be depositedupon it and intimately to unite therewith. The application of theintermediate metal covering to the galvanoplating of iron is a veryimportant feature of my invention. To explain, I suppose that ironis tobe coated with zinc. The latter is well known to be a metal of littleductility,

would, by the molecular working of the iron, soon be destroyed, or atleast become utterly ineflicient as a preservative against oxidation,for which purpose it is mostly used. On the other hand, as theproperties before mentioned increase in zinc in an inverse ratio withits thickness, it is desirable that the zinc coating of iron should beas thin as possible; but as a thin zinc covering could not efficientlyprotect the iron the intermediate layer of tin is used, whose ductility,elasticity, and dilatability excel those of iron and supply thedeficiency in the thickness of the zinc coating. Thus a thin, elastic,and ductile zinccovering is used, which, combined with the tin havingthe same properties, ofi'ers the thickness of coating requisite for theproper protection of the iron.

The galvanization of common metals as heretofore attempted were simplylaboratory experiments conducted on a very small scale,and which neverresulted in a manufacturing process. In such-experiments heat was resrted to as the easiest and readiest means to o tain from a givensolution the metal to be deposited. The temperature in such solutionswas allowed to reach from to and centigradei. a, from to and 200Fahrenheit.

Reasons of economy-La, the galvanization of common metals in a practicalor industrial mannerrender it important and necessary to operate at theordinary temperature. For this purpose I use solutions of such nature aswill allow of the work being carried out at the or dinary temperaturewithout ofiering too great resistance to the galvanic current. Inextremely cold weather the activity of the baths may lie excited byincreasing the electric force. I use for this purposebatteries of apeculiar construction having but one element capable of producing acontinuous current sufficient at one operation to galvanize objects ofone thousand pounds in about two cubic meters of solu tion. Thesebatteries consist of a leaden vessel 'of about one and twentyone-hundredths of a meter in width and fifteen one-hundredths of ameterin depth. The bottom of this-vessel is lined with a thin and movablecopper sheet bentup at its edges. In this vessel I barsof from threeone-hundredths to four onehundredths of a meter in thickness, and uponthese bars I put a thick sheet of zinc, to which meter in length byseventy-five one-hundredthsplace, in the direction of its longth,twowooden are secured or fixed the conductors. There is no diaphragm, andone battery thus :made is equivalent to from twelve to fifteen elementsof Daniel].

Heretofore it was deemed indispensable in electrochemicalapplications toconcentrate the solutiousin order to precipitate metal upon metal. Inthe application of the electro-chemical process according to myinvention it is of utmost importance to employ weak solutions or bathsof feeble density. This 1 consider as a vital condition, without thefulfillment of which it is impossible to operate economically or in amanufacturing way. I use solutions of density not less than 3 accordingto Baums aero'meter and not more than 6 Baum.

When during the operation, in consequence of evaporation, the solutionbecomes concentrated beyond 5 or 6 Baum, I add water in the proportionof the water that shallhave been evaporated. v The diluted state of thesolutions renders the tin, lead, and zinc salts less subject toalteration, while .at the same time it puts them in a condition mostfavorable to be est resistance to electrochemical decomposition; and Ihave found that it is easier to maintain in a soluble state subsalts,whether alkaline or acid, it used in solutions not concentrated.Ipre't'er to use the metastannates and the protocyanides of tin, eitherseparately or combined with each other or combined-with analogoussubstances of zinc or lead base; the'sub or proto sulphates and thesubacetates of zinc, 850.; combined together-in general, all doublecombinations inwhich the subsalts of the metallic base enter in butfeeble proportions. v

Having thus described my improvements in the galvanization of'iron,steel, &c., and the manner in which the same are or may be carried intoeffect, Iclaim as invention- The electrochemical galvanization of iron,

steel, &c., by combining with an intermediate metal,applied in themanner herein described, the method ofeffectin gthe galvanization properat ordinary temperature in solutions not-concentrated, substantially asherein set forth.

In testimony whereofI have signed my name to this specification beforetwo subscribing witmesses;

CH. BESLAY. Witnessesz' GEO. HUTToN,

JAMES W. BROOKS.

